The present invention is directed to transmission shifters for motor vehicles, and more particularly to improvements in transmission shifters which control the gear transmission of a motor vehicle via either a cable or an electronic control.
Transmission shifters, whether column mounted or floor mounted, are used to control the gear transmission in a motor vehicle. Typically the transmission shifter has a shift lever which is pivotable over a series of positions: park, reverse, neutral, drive and one or more lower gears, for example. Such transmission shifters can be cable actuated or electronically actuated. For cable-actuated shifters, rotation of the shift lever pulls or pushes on a cable, transmitting load to the gear transmission of the motor vehicle. In more recent years it has become desirable to have electronic controls for the transmission shifter. With electronic shifting, movement of the shift lever to each position sends a signal to the gear transmission to move to a corresponding gear position. For example, magnets and Hall effect sensors may be used, with each magnet positioned to correspond to a particular gear transmission position. Electronic shifting is desirable in that there are fewer routing limitations for electric wiring than for larger cable assemblies. Electronic shifting is also desirable to provide a xe2x80x9ctiptronicxe2x80x9d shifting option, where the transmission is shifted up or down one gear lever by moving the shift lever incrementally. That is, the shift lever is in a tiptronic position and the gear transmission is shifted up one level (for example, from second gear to first gear) by moving the shift lever in a first direction from the tiptronic position, and the gear transmission is shifted down one level by moving the shift lever in a second direction, often a direction opposite the first direction. For examples or electronic shifting and tiptronic shifting see U.S. Pat. No. 5,070,740 to Giek et al and U.S. Pat. No. 5,791,197 to Rempinski et al.
However, an entirely electronically controlled shifter can be expensive because of the need for an electric starter motor strong enough to move the gears in some instances, e.g., when parked on a steep hill. Moreover, if the transmission was in the park position and there was a power failure, additional means would be required to move the transmission out of the park position, increasing the overall cost of the assembly.
Accordingly, there is a need for a transmission shifter capable of electronic-actuation while also being capable of cable actuation in some instances. In view of the foregoing, it is an object of the present invention to provide a transmission shifter which is of simple construction and low cost, and which is capable of changing the gears of a motor transmission by both cable-actuation and electronic-actuation. It is an additional object of the present invention to provide a transmission shifter that is highly reliable in operation, which can be manufactured efficiently, which is of an elegant design having fewer parts, less weight, less tooling and machining requirements and overall reduced cost while at least maintain high quality and reliability in shifting. Additional objects and optional features of the invention will be apparent form the following disclosure and detailed discussion of preferred embodiments.
In accordance with a first aspect, a transmission shifter for controlling a transmission of a motor vehicle by both a cable and an electronic control comprises a base, a cable attachment bracket mounted on the base and pivotable about a first axis, and a shift lever. The shift lever is mounted on the base and is pivotable about the first axis along a first shift path. In a first segment of the first shift path the shift lever is movable in a cable-actuation mode and the shift lever urges the cable attachment bracket to pivot about the first axis. In a second segment of the first shift path the shift lever is movable in an electronic-actuation mode, and the shift lever does not urge the cable attachment bracket to pivot about the first axis.
In accordance with another aspect, the shift lever of the transmission shifter is pivotable about the first axis along the first shift path, and in a first segment of the first shift path the shift lever is movable in a cable-actuation mode between a park position, a reverse position, and a neutral position, and in a second segment of the first shift path the shift lever is movable in an electronic-actuation mode to at least one lower gear position.
From the foregoing disclosure and the following more detailed description of various preferred embodiments, it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of shift assemblies. Particularly significant in this regard is the potential the invention affords for enhancing transmission control options available to a driver of a vehicle. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.